1. Field of the Invention
The present invention relates generally to a circuit device, and more particularly to a circuit device for controlling a plurality of light-emitting devices in a sequence.
2. Description of the Prior Art
Poor illumination at night is a set back to night activities. There may be problems of difficult identification and safety. People jogging or cycling at night may be hit by cars due to insufficient illumination. Playing balls in open places may have to be stopped at night if the street lights are not strong enough. It is therefore necessary to find means to enhance the safety and smooth-going of night activities.
Footwear with flashing device is available on the market for reasons of safety described above. Such footwear typically includes at least one light source such as light emitting diodes (LEDs), a source of power such as a battery, and a switch to connect the battery to the light sources to illuminate them.
In addition, the switch could be a simple manual switch as disclosed, for example, in U.S. Pat. No. 4,158,922. The switch could be a mercury switch in which a ball of mercury runs back and forth along a tube between a pair of electrical contacts during motion of the footwear, as disclosed in U.S. Pat. No. 4,848,009. The switch can be a pressure responsive switch which opens and closes in response to application of the wearer's weight on the switch as disclosed, for example, in U.S. Pat. No. 5,285,586. The switch can be a spring switch in which a cantilevered spring in the form of a coil oscillates back and forth to make and break contact with an electrical terminal as, for example, shown in U.S. Pat. No. 5,408,764.
Moreover, to increase battery life and to provide a more attractive eye-catching and safer display, it is desirable to cause the lights to flash on and off, rather than being maintained continuously illuminated while the switch is closed. Such flash will be interesting and attractive if an eye-catching flashing pattern could be demonstrated from the LEDs.
Furthermore, to prevent the aforesaid device from the water and dust and therefore to extend the lifetime of such device, the system-in-package of the battery, the responsive switch, and the control circuit of the LEDs is also desired.